George Tiller

AP

When Dr. George Tiller, the U.S.'s best-known provider of late-term abortions, was shot in the head on the morning of May 31 while serving as an usher at his Lutheran church in Wichita, Kans., both sides of the abortion debate braced for battle. Supporters called him a martyr; critics called him a murderer. Both groups deplored his killing: abortion-rights activists warned that it could signal a fresh wave of clinic violence; abortion opponents warned that it would lead to the demonizing of their movement.

Tiller, who had originally planned to become a dermatologist, lived with the knowledge that his actions made him a target. There are only a handful of clinics in the country where women can obtain an abortion late in pregnancy; Tiller's was bombed in 1986. In 1993 he was shot in both arms. He received death threats regularly, wore body armor and traveled with a guard dog. Just a few weeks before the shooting, the clinic's security cameras and lights were vandalized; Tiller asked the FBI to investigate. He was repeatedly tried  and acquitted  on charges of violating state laws governing late-term abortions. Why did he do it? "Women and families are intellectually, emotionally, spiritually, and ethically competent to struggle with complex health issues  including abortion," he said, "and come to decisions that are appropriate for themselves."

The abortion debate typically occurs within the boundaries a democracy sets, ones of peaceful, if not always respectful, debate and advocacy on both sides. But Tiller's murder reminds us that in matters of life and death, the argument itself can become a matter of life and death.